This invention relates to a variable frequency lighting peg adapted to be installed at the center of road intersections, and constructed so that when a vehicle is approaching the intersection along one of the roads, the rate of pulsation of light emitted from the peg to another road can be varied for warning the driver of a car coming along the second road to exercise caution with respect to the approaching vehicle on the first road.
Various lighting pegs have been heretofore proposed.
For instance, Japanese Utility Model Laid-Open Publication No. 152013/1986 discloses a road-surface mounted type of signaling device comprising a solar cell, battery, and a light-emitting diode, and that determines the light intensity of the surrounding area, and that is automatically operate so that the light pulsates throughout the night. Also, in an automatic flashing lamp indicating the edge (or shoulder) of a road, a first photoelectric conversion element senses the ambient light, while a second photoelectric conversion element senses light from a vehicle so that the lamp operates to pulsate (refer to Japanese Utility Model Publication No. 39915/1977). Otherwise proposed is a self-lighting type of road marking device wherein ambient light is detected from the output voltage of a solar cell, while light from a vehicle is sensed by a photoelectric conversion element, and a light emitting diode is thereby operated so as to pulsate (for instance refer to Japanese Utility Model Laid-Open Publication No. 68113/1986).
As a result of recent traffic clogging in the majority of principal roads, back roads of narrower widths tend to be utilized as detours. Ordinarily, the provision of regular traffic signals is not sufficient in these back roads, and therefore lighting pegs and the like of the automatic flashing type are frequently used to supplement the traffic signals. However, since there is a limitation in the capability of such auxiliary devices, the number of traffic accidents occurring in the back roads is constantly increasing and a counter measure to this problem has been urgently required.
Among the aforementioned conventional techniques, a lighting peg that operates to pulsate throughout the night is adapted to indicate the presence of an intersection of roads, and to warn drivers of vehicles and pedestrians to exercise caution. However, the reason for most of the intersection accidents is in the disobeyance of temporary stopping rules and carelessness of drivers of vehicle coming along the other road from either the right or left directions. Therefore simply indicating the presence of an intersection is not sufficient to preventing such accidents.
In another of the conventional techniques where the peg pulsates only while a vehicle approaches the intersection, the presence of the intersection is not indicated to pedestrians or the riders of bicycles. Furthermore, when a vehicle comes along a first road of an intersection, and thereafter another vehicle approaches the intersection along another road, the approach of the second vehicle is not informed to the driver of the first-mentioned vehicle, and therefore such a technique cannot be considered to be satisfactory.